Silent-typewriter type-head-actuating mechanism



March 24,1925.

W. P. KIDDER SILENT TYPEWRITER TYP HEAD ACTUATING MECHANISM Original Filed June 15, 1921 S y2, F/

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Original Filed June 15, 1921 3 Sheets-Sheet 2 March 24, 1925.

W. P. KIDDER SILENT TYPEWRITER TYPE HEAD ACTUATING MECHANISM original Filed June 15, 1921 3 Sheets-sheet s oooooooooavooodooooooooooooo luvenot Patented Mar. 24, 1925.

UNITED STATES PATENT OFFICE. f

WELLINGTON PARKER KIDDER, OF ROCHESTER, NEW YORK, SSIGNOR '.lOl ROCHESTER INDUSTRIES, INGWO'F ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

SILENT-TYPEWRITER TYPE-HEAD-ACTUATING MECHANISM.

` Application filed June 1.5, 1921, Serial No. 477,648. Renewed .Tuly 7, 1924.

` To all whom t may concern.'

Be it known that I, WELLINGTON PARKER KIDDER, citizen of the United States, and a resident of Rochester, in the county of Monroe and State of New York, have invented certain new and useful Silent-Typewriter Type-Head-Actuating Mechanism, of which the following is a specification.

This invention relates to typewriting machines, its objects being to-produce compactness and lightness of weight in silently operating typewriting machines; to reduce the expense of construction and assemblage thereof; to effect such a mechanical construction of a low cost sheet metal base that the type heads will be guided positively to the impression point without lateral wobbling; that is, in trade parlance, without throwing the type off their feet; to apply the pressure of the type head actuating mechanism on the type head closely adjacent to the printing characters on the type head for more effective impression, especially in manifolding; to provide for easy adjustment of the type heads relatively to the platen; and to Vincorporate in the platen shift mechanism means for so supporting it that its weight will be greatly diminished relatively to the pressure required to be exerted by the operator in shifting the platen to bring the impression point to different heights for impression of any one of a series of printing characters on a type head one above another. The sheet metal base, considered fromV the View point of lightness of Weight, cheapness of construction, economy of labor 1n assemblage and mechanical efliciency, is a most important feature of this invention. .The base described is made from a stamped, sheet metal blank and, compared with a similar base made of separate parts greatly reduces the number of parts to be made and assembled, the reduction in number being from seventeen parts as heretofore proposed by me to one part; and at the same time such a rigidity is given to its integral, vertically slotted guiding webs descrlbed below that all transverse canting or wobbhng of members of each type head actuating mechanism guided by such slotted webs is practically eliminated.

In the accompanying drawings forming a uent mechanism shown in detail in other figures.

Fig. 2 is a sectional elevation from front to rear of the machine corresponding to line 2 2 of Fig. l and looking in the direction of the arrow shown in Fig. 1. This view mainly illustrates one of aplurality of type head actuating mechanisms all of which are identical except in the shape of the key levers. This view shows a type head at impression point, the type head having three printing characters spaced apart one above another and the intermediate character being at the impression point. The view also indicates parts of the paper carriage shifting mechanism whereby the carriage is raised or lowered to bring the impression point of the platen in linewith any one of the printing characters on the type head.

Fig. 3 is a view mainly showing a type head actuating mechanism with the type head in its most forward position away from the platen. The view also illustrates means for partially supporting the weight of the paper carriage, and is partiall dotted in plan, in section at line 2-2 of ig. 1.

Fig. 4 is a top plan view of a lengthwise (enlarged) adjustable, forked, supporting bracket with one of which each type head actuating mechanism is provided.

Fig. 5 is a side elevation of the bracket shown in Fig. 4.

Fig. 6 is an elevational view showing the rear end of the bracket shown in Fgs. 4 and 5 in connection withthe under end of a cam slotted toggle lever carried by it.

Fig. -7 is a top plan view, and

Fig. 8 a side elevational view of said cam slotted toggle lever which forms a member of the type head actuating mechanism.

Fig. 9 -is a top plan view, and

Fig. 10 a side elevational view of a toggle member which connects a type head with a cam slotted toggle lever such as shown in Figs. 7 and 8.

Fig. 11 is a side elevation, and

Fig. 12 an end elevation of a bow shaped lever forming a member of a type head actuating mechanism.

Fig. 13 is a top edge view of a type head, and

Figs. 14 and 15 are respectively side and i charactered elevations of the type head.

Fig. 16 is a top plan view of a flat, smooth sheet metal, main frame forming blank. Fig. 17 is an end elevation of the sheet metal main frame formed from the blank shown in Fig. 16.

In that form of the invention now set forth, (Figs. 16 and 17) the main frameor base of the machine is made from a stamped and bent sheet metal blank having a rectangular smooth horizontal top 1 which forms a level table on which the under edges of the type heads are slidably supported. The rectangular top 1 is provided with a lengthwise transversely extending arced slot 2, the concave side of which is rearwards. Members of a type head actuating mechanisms work through this slot. The flat blank is bent along the dotted lines a to form the horizontal dependent end walls 3 of the base and kalso to form a rear dependent vertically slotted guide web 4 and a front dependent vertically slottedguide web 5. The guide slots in each web are indicated by 6. The end forming portions 3 of the flat blank extend rearwardly beyond the rear edge ofthe web 4, and each end portion 3 is formed witha recess 7. Adjacent each junction of the dotted lines a inwardly of a corner portion of the rectangular portion 1, a corner of each web 4 and 5 is cut out at a as required by the punch and die. Dotted lines a2 indicate lines for bending the flat blank to form inwardly projecting marginall portions 8 of the base. Each outward corner of the web 4 and of the web 5 is formed with a projecting lug 9, each having a pin hole 1() which when the blank is bent into the base forming shape shown in Fig. 25 registers with a pin hole 11 in an end portion 3, whereby the dependent ends 3 and the dependent webs 4 and -5 of the blank when bent into base forming shape shown may be pinned or anchored together to keep the dependent members inl fixed relation one to another. Of course, such anchorages of the dependent members of the base may be otherwise effected than by the construction stated.

Referring to this sheet metal blank in its base forming shape, the upper end of each rear upstanding margin 8 is perforated at 12 for connection with the rear of a transverse rearwardly extending impression resisting and paper carriage guide bar described below. Each end 3 is perforated at 13 for reception of a' rear pivot of a swingable rocker arm carrying a cam roll of a paper carriage shift mechanism. Similarly, the ends 3 are opposedly perforated at 14 for reception of a transverse cam carrying rocker shaft forming a part of the carriage shift mechanism. The under margin of the rear guide web 4 is provided with a row of holes 15 each opposite the under end of a guide slot 6 and spaced apart by an imperforate marginal portion 16 of the web 4. The holes 15 severally receive the rear end of a coiled spring forming part of the type head actuating mechanism, and the imperforate margin 16 closes the under ends of the guide slots 6 and the dependent guide web 4 is bent downwardly and forwardly as indicated in Fig. 16. The ends 3 are opposedly formed with an anchorage hole 17 for the ends of a straight transverse rod on which the rear ends of the type head actuating levers are hooked. The rear ends 3 are also formed with opposed bearing holes 18 for a straight transverse wiper cam carrying stationary pivot shaft, the wiper cams severally support the type head key actuating levers between the ends of the levers. So

also the ends 3 are opposedly formed with holes 19 for supporting the ends of a transverse rocker shaft that forms a member of the carriage shift mechanism. One of the ends 3 is formed near its rear upper corner with a hole 20 for supporting a member of the carriage shift mechanism. The flat table-like top 1 of the base is formed with holes 21 in arced relation one to another adjacent the front edge of the arced opening 2 for support of vertical spacing means which support a transverse arced bar at the front of the machine and forwardly of the opening for carrying a series of brackets each forming a part of a type head actuating mechanism. Rearwardly of the opening 2, the top l is formed with openings 21u for reception of vertical spacing means which carry anl upper demountable transversely extending arced type head cover plate. The rearward corner projections of the flat blank are formed with right angular recesses, one wall 22 of which forms a horizontal bearing for an end of the impression blow resisting andfcarriage guide bar, and the rear upstanding edge 23 of which forms a rear abutment or bearing for an end of such bar.

Referring to Fig. 2, upright vertical spaces 24 are severa l located at each hole 21 of the base, and a screw 24n passes upwardly through a hole 21 and through the bore of a spacer into a transverse, arced, horizontal bracket supporting bar 25 at the front side of the machine, the rear concave edge of this bar being approximately coincident with the rear edge of the arced opening 2 through the base top 1. The front edge of the bracket supporting bar 25 is provided with a series of threaded openings,

each forabracket adjusting screw 26, the head of which projects above the upper surface of the bar.

The type heads are reciprocated in radial paths to the impression point, and the type head actuating mechanisms are, except for the transverse shape of their key levers, identical one with another iu construction and mode of operation.

Each type head actuating mechanism comprises a bracket 27 (Figs. 4, 5 and 6) having a dependent arm 28 and a rearward lug 29. Its for-Ward under corner is provided with a shoulder 30 for engagement with'the head of the adjusting screw 26. Its forward upper portion is provided with an elongated slot 31 and its rear end lug 29 is forked to form a forked space 32 from top to bottom of the rear end of the lug 29, which over-hangs the opening 2 through the base top. Each bracket 27 is held to the bar 25 -by a clamp screw 27a through the elongated slot 3l. By loosening the screw 27'a and adjusting the adjusting screw 26, the bracket 27 may be endwise adjusted for adjustment of a type head in operative connection with the bracket. By a transverse pivot pin 33 the forward transversely perforated lug 34 of a front cam toggle lever 35 is pivoted in the forked space 32 of the bracket, the fork arms of which over-lap the lug 34 and keep it from lateral vibration during its movements. This toggle member 35 has, opposite the lug 34, a projecting horn 36 at the base of which is a pivot hole 36a for reception of a transverse pivot pin 34a. This tog le member 35 has a lengthwise curved cam s ot 37. In the assemblage, the pivot pin 34n pivotally connects the front end of a rear toggle member 38 in the form of a link having front fork arms 39 and rearward fork arms 40, each of which has near its rear end a hook 41, one hook being laterally opposed to the other and the hooks being open on the upper side of this toggle member or lilik 38. The fork arms 39 receive between them the bodyof the front cam toggle member 35 rearwardly of the pivot pin 34, the horn 36 being slidable between the fork arms 39 whereby at this point of the mechanism lateral vibration adjacent the pivot pin 34 of the two toggle members, one in relation to the other, is overcome. The rearward `fork arms 40 of the rear toggle member 38 receive the type head carrier; the type head itself being indicated by 42 and being shown with three printing characters spaced apart vertically one above the other. The carrier itself is indicated by 43, and is a short rectangular plate, the weight of which is reduced by an opening .fr in its body. This plate is thin, and has an upper and also a lower forwardly extending arm 44, the arms being made as shortas feasible and vertically connected by an integral, upright member 45. Midway between the upper and under edges of themembers 44 the carrier is provided with a transverse Apin 46 which projects on each side of the carrier. The fork arms 40 of the rearward toggle member 38 receive the type head carrier 43, the hooks 41 of the toggle member receiving the ends of the pin 46. Which is closely adjacent the printing characters on the rear vertical edge of the type head. By spanning or embracing in sliding connection the sides of the type head carrier 43 the fork arms 40 of the rear toggle member 38 at all times prevent lateral wobbling or vibration of the type `head which, in operation, is reciprocated back and forth on the smooth surface of the base top 1, towards, and from the platen P. 'The upper edges of the members 44 of all the type heads are covered by and are in sliding contact with the under surface of a transverse arced type head cover plate 48, the ends of which are held to the base top 1 by screws 49 through upright spacers 50 resting on the base top 1, this cover plate being mounted rearwardly of the opening 2 in the base top. The screws 49, or other fasteners, are anchored in the base top and the plate 48 is readily detachable. The under edges of the hooks 41 are curved at 41a and in the working assemblage bear upon the ends of a transverse pin 47 through and projecting from each side of the type head carrier below the pin 46. This construction permits the type heads and carriers to be quickly disconnected with the toggle members 38 on removal of the cover plate 48, and by this means permits the machine to be provided with a series of type heads of -any desired style of printing char acter in a given language, and also permits type heads carrying the printing characters of one language to be readily substituted for type heads carrying the printing characters of another language, whereby the machine `becomes adapted for use in writing in va- ,type heads and carriers in upright position,

and makes it unnecessary to form the flat smooth horizontal base top l on its upper surface with radial guide grooves, and to form the under surface of the cover plate 48 with corresponding guide grooves for the type head carriers, and this obviates a considerable item of expense heretofore attending production of toggle link actuated type heads and involved in the milling of upper and under, either or both, radial guide grooves for guiding the reciprocating type heads to the impression point. The forward cam toggle member 35 is vibrated for reciprocating the type head to and from the impression point by means of a suitable lever,

link and impression key construction in which, as now shown, a bow shaped lever 51 has its forward and under end provided with a pivot pin hole for reception of a pivot pin 52, by which, the lever is pivotally connected to the under end of the dependent arm 28 of bracket 27. The bow shaped lever 51 is made up of two side plates, which at one end embrace the under end of the arm 28, and are thereby spaced apart and also held together in sliding relation to the sides of the depend-ent. arm 28 by the pivot pin 52, the other end of the two plates which oonstitute the bow 51 being spaced apart by a cam roll 53 and held together by a cam roll pivot pin 54. The cam roll 53 works in the cam slot 37 of the front toggle member and the side plates of the bow shaped lever embrace the rearward walls of the forward cam lever and thereby assist in keeping the toggle members and the type head carrier from the lateral wobbling or vibration above referred to. The sides of the dependent arm 28 are spaced apart by a spacer 51n which is riveted in place at 28a.

To the bow shaped lever, between its ends, there is pivoted at 55 the upper end of a dependent link 56, the under end of which is pivoted at 57 to an impression key lever 58. The bow shaped lever 51 and its link work through the opening 2 in the base plate top and the impression key lever 58 is located below the top of the base. The impression key lever 58 is formed, at its rear end, with a dependentintegral lug 59 and is also formed, at its upper rear corner with a reentrant recess 60 in its upper edge which permits the impression key lever and all of them to be hooked upwardly against the transverse impression 'key lever pivot rod 61, which extends straight across the machine and has its ends anchored in the holes 17 of the base ends 3. The impression key lever 58 has, near its front end, an integral dependent projection 62, its front. end being upturned and provided with a button head 63. The downward projections 59 and 62 of the impression key lever, which is made of thin sheet metal, are located in and in all positions work between and in sliding con- 'tact with the edge walls of the slots 6 respectively in the rear dependent web 4 and in the front dependent web 5 of the sheet metal base. Thus the impression key lever is, at its rear end and adjacent its front end, kept from lateral movement during operation; andit is particularly in this connection that the integral formation of the guide slot members L1 and 5 of the sheet metal frame becomes of considerable working importance, because if these front and rear slotted guides were made in pieces separate from the frame and thereto connected by screws, or other fasteners, they would be apt to werk loose to some extent during the operation of the machine, and involve adjustment from time to time in order to keep all the above described members of the series of type head actuating mechanisms from such lateral wobbling or movement as would tend to throw the type off their feet at the impression point. But, obviously the desirable rigidity of the slotted guide -members 4 and 5 of the frame might be effected by welding or brazing them as separate pieces to the frame in order to give them the desired and proper rigidity. Each impression key lever 58 rests, in the present construction in bearing contact, on a rockable, ovalish shaped wiper cam 64, the under end portion of which is pivoted on a transverse straight stationary shaft 64a, the ends of which are fixed in the holes 18 of the base ends 3. The forward camming surface 65 of the upwardly extending wiper cam 64 contacts with the under edge of the impression key lever 58; and the rear cam edge 66 of the wiper cam co-operates with an impression key lever return spring, the under edge of the wiper cam below the pivot shaft 64 being rovided with a lug 67 in which the forwarld end of a forwardly straight portion 68 of a coiled spring 69 is connected. The rear end of the return spring 69 is anchored in the hole 15 in the marginal portion 16 of the rear` dependent base web 4. Whenever an impression key lever is depressed against the wiper cam, with which its under edge is in constant contact by reason of the tension of the coiled spring 69, the wiper cam is correspondingly depressed to rock the cam surface 66 gently and progressively upon the straight portion 68 of the spring to increase the tension thereof. Hence, the operation of the machine in this respect is at all times silent. It will be observedthat because of the short length of the type head carrier the type head actuating mechanism may be made exceedingly short, whereby a very compact or narrow machine from front to rear is obtainable, with a decrease in its weight, compared to prior art machines having toggle length impression key actuating mechanisms.

As already indicated, the effectiveness of the present machine for use in manifolding is greatly enhanced by connecting the type heads closely adjacent the printing characters to the toggle link members, the effective impression behavior of which is also enhanced by the relatively short length construction of the several identical type head actuating units or mechanisms assembled in the complete machines, and which are provided with a. standard key-board having three parallel rows of impression keys at the front of the machine and in rear of the usual spacci; bar S indicated in Fig. 1. For

silencing the forward movement of the type.

head actuating mechanism I mount an arcuate thin sheet metal pad carrier which is L shaped in cross-section on and over the upper edges of the bracket 27, clamping the under horizontal web of the carrier 7 O to the brackets by the screws 27a, and providing the pad carrier with an arced shape upstanding pad 71 of soft material, the rearward face of which forms an abut ment for the front edges of the forward toggle link or member 35, and the co-operating forward end -portion 39 of the rearward toggle -link or member 38, so that when the coiled spring 69, which is put under tension by a. depression of the key lever, causes thewipcr cam to move upwardly and thereby rock the therewith connected link 56, bow lever 51, cam toggle member 35 and rear toggle member 38 forwardly, the shock` attending such movement is absorbed by the pad71 with its wall opposed to all the impression key actuating mechanisms.

It is desirable to provide the base top 1, about midway between its ends, with a brace provided with bearings for transverse rocker and stationary shafts comprised in the machine, and this brace is indicated by 72. It has horizontal end flanges which arey fixed rearwardly at 73 to the under surface of the base top, and forwardly at 74 to the under surface of the base top by one of the screws 24. It is shown recessed on its upper edge, and provided with a rearward eXtension, having a Hange 7 2 abuttedv against the margin 16 of the rear dependent guide web -4. Its under edge is provided with a hole through which the pivot shaft 64* passes in fixed contact, and forwardly thereof with another hole forming a bearing for a rocker shaft to be described. This brace adds to the rigidity of the frame and of the. rear vertical slotted guide web 4 of the base. l

The platen P is, as usual, carried by an endwise movable paper carriage having vertical end plates 75, a transverse back member 76, and on its rear side a straight bearingk web 77 in sliding contact with the forward wall of a straight transverse impression blow resisting and carriage guide bar 78, which in the 'present construction is anchored on the horizontal walls 22 of the base ends 3, and supported at each end by such walls and rearwardly by the vertical walls 23 of the base ends, secured by rivets in holes 12.

I do not herein show, either in connection with the spacer bar S or otherwise, any escapement mechanism for moving the paper carriage endwise. Such escapement mecha.- nism does not form a feature of my present invention. I do, however, indicate in the drawings an escapement rack bar R of usual construction in its proper location.

For shifting the paper carriage and platen vertically to bring the impression point into opposition to any one of the three printing characters on the vertical face of the type head, the vertical end plates of the paper carriage are transversely rigidly connected by a tube 79, the under wall of which is lengthwise slotted at 80. The slotted tube 79 is mounted slidably on a transverse rod 81, end portions of which are each fixed to the upturned end 82 of a rocker armV 83, the two rocker arms 83 ,being each pivoted at their rear ends on studs 84 fixed in holes 13 of a base end 3. Thus the paper carriage is` endwisel movable on the transverse oscillatable supporting rod 81, carried by the forward ends of the rocker arms that project from the rear side of the machine into the transversely extending paper carriage path, the paper carriage having its ends projectible beyond the base ends by reason of the base end depressions at 7.

Between its ends each rocker arm 83 carries a laterally projecting cam roll 85; one of the cam rolls at the right hand end of the machine working in a cam path 86 of a rocking cam 87 which, in Fig. 1, is located at the under end of the drawings, which is the right hand end of the machine as one faces the key-board. This cam 87 is fixed on one end of a straight transverse rocker shaft 88, the ends of which are journaled in the opposed bearing holes 14 of the base frame near the rear under corners thereof. ,Y

A corresponding cam 87a for the carriage shift mechanism is mounted on the normally left hand end of the` rocker shaft 88, as indicated in Fig. 1.

Returning to the cam 87 it has pivoted to it at 89 above the rock shaft 88, the rear end of a forwardly extending link 90, the forward end of which is pivoted at 91 to the under end of a rocker arm 92 of the rocker shaft 93 which is journaled in the holes 19 of the base ends 3. The carriage shift mechanism described below comprises a shift key lever, depression of. which rocks the shaft 93 and consequently rocks the cams. 87 and 87a.

Outwardly of the right hand cam 87, the rocker shaft 93 has fixed to it a cross-bar 93*3L each end of which is provided with a buer roll 94 which is positioned to come into silent contact with a buffer pad 95, located forwardly of the buffer rolls.

The impression key levers are variously bent between their ends as at y (Fig. 1) in order that the rear end portions thereof may be straight and parallel one to another, for some distance forwardly of the transverse pivot rod 61 on which they are hooked, and at the same time be operative to effect the radial travel of the type heads to the impression point; and also have their free ends provided with the impression key tops K2 arranged in rows as in a standard keyboard, and as illustrated in Fig. 1; and an important reason for having the rear end portions y of the impression key levers straight and parallel is that they may thereby be in a position for properlyk contacting with the front edges 65 of the wiper cams 64, which are laterally parallel one with another and project at right angles to the axis of the stationary transverse pivot shaft 64a on which they are loosely mounted. These wiper cams are in lateral sliding contact one with another, and at the opposite ends of the series of wiper cams, they are held in place by collars 128, as indicated in Fig. 1, on the front shaft 61.

While the paperv carriage member 77 is always in sliding contact with the transverse bar 78, .the slight are of movement given to the axis of the carriage supporting rod 81 does not, in practice, cause the member 77 to bind against the bar 78, and it is to be noted that the rack bar R is fixed to the slit tube 79 and forms a fixed member of the paper carriage.

The rear vertical .portion of the carrier 43 has a forward enlargement 43 whereby the rear or printing character carrying end of the short type head is stilfened suiciently to form a pivot pin bearing so that the pivot pin 46 is easily made stiff and rigid enough for eicient working relations between its ends and the walls of the hook recess 41. By the' fork arm construction and lateral bearing surface arrangement, already described, of the toggle links comprised in the type head actuating mechanism as well as of the type head with one of the toggle links and also of the bow shaped toggle link actuating lever 5l and the similar arrangement of the forward toggle link member 35 with the bracket 27, these members of the type head actuating mechanism are laterally self-resistant to those lateral vibrations which would impair impression if they existed; and while toggle link members are old in a silently operating typewriter for movingl a type head radially to an impression point when its key lever is depressed, yet, in the present construction,

so far as I am advised, what I have referred to as a construction that is laterally selfresistant against the undesirable lateral lwobbling of these members is new in the present construction. It is also important.V

because it enables these members to be automatically sustained in proper working relation one to another and to the impression point 'without going to the expense of millmg guide grooves for the type heads in the under and end type head supporting plates; and with a type head of the short length now proposed, to wit; ofabout 1 in actual practice, it would be impossible to provide the ltable top 1 and the cover plate 46 with verticallyopposed radial guide grooves that would not necessarily run one intothe other as they approached convergingly near lo the printing point.

Where, as in the priorl art comparable construction, the type heads have been of an actual working length of 21/2, it has bfen mechanically possible, as is well known, to

form independent guide grooves such as alluded to, without the guiding grooves running one into another adjacent the printing point at which the guide grooves are converge-nt. Therefore, by shortening the type heads as already indicated, I produce a more compact machine, viate the expense of milling the type head supporting plates in order to produce guide grooves, and by making the principal moving members of each type head actuating member or unit laterally self-sustaining I obtain that full lateral control for preventiop of lateral wobbling which is so essentia The rear edge of the smooth surface table top is provided midway between its ends and closely adjacent the printing point on the platen with upstanding type head side guidesv 1a of known form but forwardly of these upstanding guides which are useful merely closely adjacent to and at the moment of impression, the table top is plain surfaced. The t ype-head side guides 1 are impression point guides for the type-heads, but between these guides and the slot 2 the table top 1, or type-head under supporting plate, and the cover plate 48, are smooth surfaced, and the under and upper edges of each type-head are laterally unguided by guide-way forming members during their reciprocation from their most forward positions to the impression guides 1a. Due to the anti-wobbling guidance of the toggle link members, each type-'head may be reciprocated properly to the printing point, yet each of the so actuated type-heads has such a capacity of lateral movement that if a plurality of them are accidentally driven simultaneously to the impression point, they will be severally drawn back by their return springs. This capacity of what may be called automatic release and return from lateral contact of` two or more typeheads at the impression point, is of demonstrated practical importance for high speed work on machines embodying this invent-ion.

lVhat I claim is:

1. In a typewriting machine, the combination ofa pivoted impression key-lever; a pivoted wiper -cam provided with opposed and upper and under cam surfaces and located with the upper cam surface in the path of the impression key-lever and with the under cam surface opposed to a straight portion of a coiled return spring, the key leverl bearing continuously on the upper cam surface; and said coiled return spring y reduce its weightand obmounted with its straight portion in the path of the under cam surface and having one end anchored to the machine frame and the end of its straight portion connected to the wiper cam.

2. In a typewriting machine, the combination of a platen; a series of pairs of inter-bearing toggle links resistant at their connections to lateral movement, each pair of toggle links being operatively connected with a toggle link actuating lever operatively connected with an impression key lever; such toggle link actuating lever and such impression key lever; a substantially short length type-head operatively con`- nected with one of each toggle links closely adjacent a printing character of a t pehead and forwardly of such printing lcharacter, the type-head having a forwardly projecting portion embraced between a forked rear end portion of the toggle link connected 'to the type-head; a fiat surfaced under support for all the type-heads, the typeheads being laterally unguided in their reciprocation to and from the impression point except by interbearing relations each to the toggle link with which it is connected; whereby a plurality of type-heads if forced simultaneously to the impression point into contact one with another, will be then movable sidewise for several automatic return under the influence each of a return spring; and for each type-head actuating mechanism a return spring.

3. In a typewriting machine the combination of a 4sheet metal main frame having integral dependent end supports and integral dependent vertically slotted side webs and integral laterally opposed rearwardly extending members oppositely recessed on their upper edges to permit an endwise movable paper carriage to be projected endwise beyond either end of the'frame; an endwise movable, vertically adjustable paper carriage; a paper carriage shifting mechanism;

ya type-head provided with a plurality of prmting characters spaced apart one from another and reciprocatable from and towards the printing point in a path radial to the printing path; a type head actuating mechanism comprising a key lever pivotally mounted under the main frame, the latter having an opening for upward extension of andto permit theworking through said slot of a member of the type-head actuating mechanism; and the impression key leve1` being mounted for lateral restraint in the vertical slots of the dependent slotted webs of the frame. M

4. In a typewriting machine thecombination of a sheet metal main frame having integraldependent end supports and integral dependent vertically slotted webs and integral laterally opposed rearwardly extending members oppositely .recessed on their upper edges to permit an endwise movable paper carriage to be projected endwise beyond either end of the frame; an endwise movable, vertically adjustable paper carriage; a paper carriage shifting mechanism; a type head provided with a plurality of printing characters spaced apartone from another and reciprocatable from and towards the printing point in a path radial to the printing path; a type head actuating mechanism comprising a key lever pivotally mounted under the main frame, the latter having an opening for upward extension of and to permit the working through said slot of a member of the type head lactuating mechanism, such mechanism comprising toggle link members; and the impression key lever being mounted for lateral restraint in the vertical slots of the dependent slotted webs of the frame.

5. In a typewriting machine the combination of a sheet metal main frame having a smooth surfaced horizontal top, integral dependent supporting members and integral dependent webs vertically slotted; a vertically shiftable paper carriage; a paper carriage shifting mechanism; a type head reciprocatable over said smooth surfaced horizontal top, and provided with a plurality of printing characters spaced apart one above another; and a type head actuating Vmechanism comprising toggle links and an impression key lever pivotally mounted below said top and having lateral surfaces working in said vertical slots.

6.'In the combination stated in claim 5, the type head actuating mechanism members being constructed, mounted and operable with laterally opposed contact bearing surfaces operable to make the members laterally self-sustaining without contact of lateral margins of the type head with guiding means forwardly of type head. guides closely adjacent the printing point; and type head guides for the type head and fixed to said top closely adjacent the printing point.

As anew article of manufacture, a v

sheet metal main fralne for a typewriting machine comprising a horizontal Atable top formed with an arced opening, the concave edge of which is rearwards and which has other edges radial to the center of the circle from which the arc is struck, and having integral, dependent end supports Iand an integ'al, dependent, vertically slotted guide we 8.`As a new article of manufacture, a sheet met-al main frame for a typewriting machine' comprising ahorizontal 'table top; integral, dependent end supports; integral, dependent front and rear vertically slotted guide webs spaced apart one from another; and an integral rearward edgewise upstanding extensionA of each dependent end support, such extensions being laterally opposed integral, dependent end supports; integral,

dependent front and rear vertically slotted gulde webs spaced apart one from another; and an integral rearward edgewise upstanding extension of each dependent end support, such extensions being laterally opposed one to the other and each havlng an upper edge portion at a level lower than the table top; and rearward thereof an upstanding lback corner portion, the top of which is higher than the table top.

10. In a typewriting machine, the combination of an impression key lever; a return spring; a toggle link type-head actuating mechanism comprising a type-head, such mechanism being operatively connected with the impression key lever; a smooth-surfaced type-head at the time of impression when tl e rtoggle links are alined, said guides being spaced apart from the retracted position of the type-head and the type-head being laterallyunguided between its forward retracted position and its position under control of said guides at the time of impression.

Signed at New York city, in the county of New York and State of New York, this 14th day of June, A. D. 1921.

WELLINGTON PARKER KIDDER. 

